The analysis of laser thermosplitting of materials by using of special geometry beams

Abstract

In this paper the numerical modeling of allocation of thermoelastic fields which are formed during controllable laser thermosplitting in fragile nonmetallic materials is executed within the limits of theory of elasticity. Modeling is executed for laser beams with a cross-section in the form of an ellipse, a circle, and the semi-ring and theirs combination. The classical circuit of realization of the given method consists of the superficial heating of a material by a laser beam and the aftercooling of this zone by means of a refrigerating medium. Thus the crack which is organized in the zone of refrigerating medium supply follows a laser beam along a treatment line. On the basis of thermoelastic fields allocation shown, that application of the classical circuit of the given method realization with the use of elliptic beams possesses a number of the disadvantages, one of which is the quick deflection of a crack from a line of influence of a laser beam and refrigerating fluid at treatment close to collateral border of the sample. Thus the crack is progressed in a direction to collateral border of the sample. It is displayed, that application of special geometry beams allows to diminish degree of effects of a treatment line closeness to boundary line of the sample on crack development. The positive effect is attained by forming a compression stress zone not only ahead and under field of a refrigerating medium effects where the crack is initialized and explicated, but also on each side of zone of a refrigerating medium effects, that in one’s turn does not allow a crack to be deflected aside. Keywords: laser cutting, thermoelastic stresses, crescent beam, crack